Pull-off mechanism for sewing-machines.



No. 706,670. Patented Aug. l2, I902.

J. L. KIEFFER. PULL-OFF MECHANISM FOR SEWING MACHINES.

(Application filed Nov. 14,, 1901.)

(Mo Model.)

4 Sheets-Sheet 1.

Witnesses: I Inventor,

w: "cams Fuchs co, PHoro-umu, WASIQWU'ON, o. c.

No.7D6.670. v Patented Aug. 12, I902.

J. L. KIEFFER. PULL-OFF MECHANISM FOR SEWING MAQHINES.

(Application filed Nov. 14, 1901.)

4 Sheets8hee1t 2.

(No Model.)

mum Mk Witnes ses: W

S y e n r 0 t t A No. 706,670. & Patented Aug. l2, I902. J. L. KIEFFER. I

PULL-OFF MECHANISM FOR sEwm-e MACHINES.

(Application med-NW. 14, 1901! (No Model.) 4 Sheets-Sheet 3.

Witnesses:

Inventor,

Attorneys No. 706,670. Patentd Aug. l2, 1902.

J, L. KIEFFER;

.PU-LL-OFF MECHANISM FOR SEWING MACHINES (Application filed Nov. 14, 1901.)

(No Model.) 4 SheatsS h eat 4.

7E II, n j{ I 73 1.9

wit esses: w yfigi'ff Inventor; i y;

Attorneys UNITED. STATES PATENT OFFICE.

JOSEPH LOUIS KIEFFER, OF MONTREAL, .OANADA.

PULL-OFF MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 706,670, dated August 12, 1902.

Original application filed August 24, 1901, Serial No. 73,201.

To all whom; it may concern;

Be it known that I. JOSEPH LOUIS KIEFFER, a subject of His Majesty the King of Great Britain, residing in the city and district of Montreal, Province of Quehec Oanada, have invented certain new and useful Improvements in Pull-Off Mechanism for Sewing-Ma chines; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. I

My invention relates to a pull-0E mechanism for sewing-machines which arefusually employed for sewing shoes and boots by the agency of a single waxed-thread chain-stitch, and it forms a division of a prior application for Letters Patent of the United States, which was filed in the United States Patent'Office on the 24th day of August, 1901, Serial No. 73,201. In machines of this class it is oustomary to employ stitch-forming mechanism embracing a curved hook-needleand a gymtory looper adapted to lay the thread around the needle and to form a chain of stitch-loops which are drawn taut; to provide a slidable presser-foot adapted to be locked-in placeiat certain times and free'to yield backwardly at other times; to employ a channel-guide and a reciprocatory curved awl, which parts are at a certainjperiod moved crosswise, so as to feed the work; to provide a yieldable gage against which the work may rest, and to provide a normallyactive tension device arranged to exert a comparatively strong tension on the waxed thread at all periods except on the removal of the boot or shoe from the machine.

In another application filed by me concurrently herewith I have disclosed a threadtake-up mechanism operating in conjunction with the normally active tension mechanism and with the stitch-forming mechanism, so as I to draw back the slack thread fromthe needle; but in the present application I have provided a novel form of pull-oti mechanism, by which the waxed thread is pulled or drawn at proper intervals from the melting-pot and the normally active tension device by a posi tively-acting feeder-arm, which is equipped with a stud or roller and is carried by a sinthe machine.

Divided and this application filed November 14. 1901. Serial (No model.)

gle lever, the latter being operated directly" by the needle-cam, thus making provision for drawing out the waxed thread by an exceedingly simple contrivance, such drawing of the thread taking place when certain ratchets are free from the restraint of an automatic pawl, such ratchets and automatic pawl forming parts o't'a thread-take-up mechanism that constitutes the subject-matter of another application filed by me ofeven date herewith, Serial No. 82,287. I have also provided a novel means for measuring the thread for eachstitch-loop as it is drawn out of the melting-pot inproportion to the thickness of .thestock or work, thereby automatically regarm on the. needle cam -controlled lever, such angularregulating-lever being linked to the slidable bar that carries the presser-foot.

The invention further consists in the novel construction and arrangement of parts,which will be hereinafter fully described and claimed. v I

In thedrawings hereto annexed, forming a part of this specification, Figure 1 is an elevation looking at. one side of a sewing-machine embodying my improvements. Fig. 2 is an elevation looking at the opposite side of Fig. 3 is a plan view of the machine with one of the cams broken away and showing certain parts in section. Fig. 4: is an enlarged vertical section through the rear part of the machine, taken in the plane of the dotted line's lpnFig. 3. Fig. 5 is a detail view of the thread-pulling fork and a part of the needle-cam-actuated lever.

The same numerals of reference denote like parts in each of the several figures of the drawings.

5 is the cam-shaft, which is journaled in suitable bearings of the frame 6,and said shaft is provided at one end with a pulley 7. As

is usual, this shaft is equipped with a plurality of cams for actuating the several working parts of the machine.

Atthefront end of the machine is arranged the looper 8 on the looper-bar or lever 9, and on one side of the looper is arranged the awlbarlO, which carries the curved awl 11. The channel-guide is indicated at 12 and the needle at 13. The work-gage 15 is carried Eby a bar 16, slidably mounted on the frame 6 and held in position by gearing from the springdrum 17. The presser-foot 18 is supported by the bar 19, that is slidably fitted on the frame and is equipped with the toothedplate 2O,

adapted to be locked in position by the dog 21. The curved needle is associated with a needle-guide 22, operatively connected with a spindle 23, which is furnished at one end with an arm 24, to which is connected a coiled spring 25, adapted to normally pull the arm toward a stop-plate 26.

At the rear part of the machine is provided the wax-melting pot 27, above which is arranged the tension-wheel 28, that is loosely mounted on the arbor 29, the latter being supported by a chambered bracket 30, which receives the gas-burner 31. This chambered bracket supports certain parts of the normally active tension device, which includes the tension-wheel 28 and a friction-disk 32, which is normally pressed toward the tension-wheel by a spring 33 under control of the hand-wheel 34. With the friction-disk 32 is loosely engaged one arm of a releasinglever 35 of the tension mechanism, and to this releasing-lever is connected a chain 36, which is attached to the lower end of an upright lever 37, which is fulcrumed at 38 on the machine-frame 6. This upright lever 37 is held in position by a spring-39, and the upper end of said lever 37 carries a yieldable arm 40, which has its front end disposed in the path of a stud 41 on one of the cams mounted on the shaft 5. (See Fig. 2.)

In another application, filed even date herewith, I have disclosed a thread-take-up mechanism which is adapted to pull the slack thread cast off from the needle 13, and this take-up mechanism is shown by'Figs. 1 to 4, inclusive. The bracket 30 is equipped with an upstanding post 31, on which is secured an arbor 42, that supports the compound ratchet 43, the same being held from rotation in one direction by a spring-actuated checkpawl 44. The ratchet is prevented from rotating in the opposite direction at certain intervals by an automatic pawl 45, which is pivoted at 46 on the post and is held in one position by a spring 47. With this auto matic pawl is engaged a rocker '48, that is pivoted at 49 on the post 31, and on one arm of this rocker is adapted to ride a roller 50, which is attached to the lower end of an angular lever 51, said angular lever being fulcrumed on a stationary arbor or spindle 52 and provided with a trundle-roller 53, that is adapted to ride in the irregular groove 54 of the take-up-mechanism cam 55. This angular lever 51 is equipped with a thread-fork 56, that is arranged to travel between the compound ratchet 43 and a thread-guide roller 57, that is provided in the thread tube or passage 58. (See Fig. 4.) The take-up mechanism, which is thus briefly described, forms no part of the present application.

designates the needle-actuating lever, which is fulcrumed on the stationary arbor 52, and this lever is provided with a rearwardly-extending feeder-arm 61, the front end of said lever having operative connection with the-means for actuating the needle-carrier, as shown by Fig. 2. The lever is also provided with an upwardly-extending lug 63, having a roller 64, as indicated by dotted lines in Fig. 2, and this roller engages with an irregular groove in the needle-cam 65, as is well understood by those skilled in the art. The rearwardly-extending arm of the needlecam lever is provided with a depending fork 66, the same being preferably clamped adjustably to the arm 61 by the screw or bolt 67. This fork is formed or provided at its lower end with the stud or roller 68 which lies above the tension-wheel 28, and the feeder-fork and its stud or roller 68 are adapted to move up and down with the arm 61 of the needle-cam lever. The described construction and arrangement of parts provides a simple and efficient means for drawing the thread in a positive manner around the tension-wheel 28 and from the melting-pot 27, and said feeder-fork and its stud 68 become effective to draw out the waxed thread from the pot on the upward movement of the feeder-arm 61.

The presser-foot 18 and its slidable bar 19 are associated with devices for automatically measuring the length of thread which may be drawn at constantly-recurring intervals from the wax-pot 27. These devices consist of a bell-crank lever 70, a stud or roller 71, and a link 72. The arms of said bell-crank lever 70 are of unequal length, as shown by Fig. 1, the same being proportioned to give the proper amount of movement to the stud 71, according to the degree of rearward movement of the presser-foot bar. The bell-crank lever 70 is fulcrumed at the juncture of its arms by loosely mounting the same on the extended end of the arbor 42, the latter adapted to carry the compound ratchet 43. The upstanding arm of the lever 70'has the rear end of the link 72 pivoted thereto, as at 73, and the front end of said link 72 is pivoted directly by the pin 74 to the rear extremity of the slidable bar 19, that carries the presserfoot 18. The long arm of the bell-crank lever extends downwardly and rearwardly from the arbor 42, so as to lie close to the tensionwheel 28, thereby making the roller or stud 71 assume a position at all times above the tension-wheel 28. The feeder-fork 66 and its stud or roller 68 are adapted to have movement relative to the stud or roller 71 on the bell-crank lever, and the position of this stud or roller 71 with relation to the tension-wheel I said measuring device being connected to a is varied in proportion to the thickness of the stock or work which is placed against the presser-foot 18. On the introduction of the work into the machine the presser-foot is shoved backward more or less, according to the thickness of the stock, and this adjustment of the foot is communicated by the slidable bar 19, the link 72, and the lever to the stud or roller 71. If the stock or work is quite thick, the stud or roller 71 is moved quite close to the wax-pot and toapoint well in front of a line drawn between the periphery of the tension-wheel 28 and the stud 68 on the vertical reciprocating feeder-fork, so thatquitea longlength of thread may be drawn out of the wax-pot when the fork 66 and the stud 68 are elevated by the proper movement of the lever-arm 61, forming a part of the needle-cam-actuated lever 60. If the thickness of the work is not so great, the presserfoot 18 is not shoved backwardly as far as in the first instance, and hence less movement is given to the stud or roller 71, thus decreasing the length of the thread which may be drawn from the wax-pot.

Having thus described my invention, what I claim as new is- 1. In a sewing-machine, of the class described, the combination of a cam carried by the shaft of the machine, a cam-lever operated thereby, a reciprocating needle-block connected to one end of said lever, pull-01f mechanism carried by the opposite end of said lever, tension mechanism from which the thread is adapted to be drawn by said pull-0E mechanism, and an adjustable stud movable to various positions across the path of the thread adjacent to and coacting with said pull-off mechanism.

2. In a sewingmachine the combination of a lever pivoted at an intermediate point, means for oscillating said lever, operative stitch-forming parts operated by the forward end of said lever, a pull-off device carried hy the rear end of said lever and movable across the path of the thread to draw a loop therefrom upon the oscillation of said lever, a cooperating measuring-stud also movable across the path of the thread on the opposite side thereof from the pull-0E device, and means for adjusting the position of said measuringstud whereby the length of the thread-loop is regulated.

3. In a sewing-machine, the combination of a two-armed lever extending from front to rear of the machine and pivoted at an intermediate point, a needle-block connected to the front arm of the lever and operated thereby, a pull-0E fork carrying a thread-engaging stud or roller through which the thread is looped and carried by the rear arm, a tension device from which the thread is drawn by said pull-0E device, and a measuring device comprising a roller movable to variable positions across the path of the thread between said tension device and pull-off fork,

spring presser-foot which presses against the work and causes said measuring device to assume a varying position in accordance with the thickness of the stock.

4:. In a sewing-machine, a two-armed needlelever pivoted at an intermediate point and having its front arm connected to the needleblock to operate the same, a pull-off fork car-' ried by the rear arm and through which the thread is looped, an oifset having a cam stud or roller on the forward arm of said lever, a rotary needle-cam with which said stud or roller engages, a tension device from which the thread passes to the pull off fork, a ratchet-wheel held against backward rotation having a thread-retaining device to which the thread passes from the pull-off fork, and a measuringdevice comprisingaspring presserfoot arranged to abut against the work being sewed, a bell-crank lever mounted on an axis in the rear of the machine a link connecting one end of said lever with the rear end of the presser-foot, and a stud 71 carried by the opposite end of said bell-crank lever and arranged to assume a position across the path of the thread between the tension device and pull-01f fork, whereby the position of said presser-foot causes said stud to proj ect more or less across the path of the thread.

5. In a sewing-machine, a pull-off mechanism comprising a tension device, a threadretaining device secured against backward rotation, a thread engaging fork through which the thread is looped and which is adapted to reciprocate across the path of the thread, a bell-crank lever one arm of which carries a stud projecting into the path of the thread between the tension device and said fork, and which is also adapted to reciprocate across the path of the thread and assume variable positions, a presser-foot carried by a sliding bar, means for resiliently holding said presser-foot against the work, and a link connected with the rear end of said sliding bar and with the other arm of said bell-crank lever.

6. In a sewing-machine, a pull-off mechanism comprising a tension device, athreadretaining device secured against backward rotation, a thread engaging fork through which the thread is looped and which is adapted to reciprocate across the path of the thread, a bell-crank lever one arm of which carries a stud projecting into the path of the thread between the tension device and said fork, and whichis also adapted to reciprocate across the path of the thread and assume variable positions, a presser-foot carried by a sliding bar, means for resiliently holding said presser-foot against the Work, means for locking said sliding bar against motion during the formation of a stitch, and a link connecting said sliding bar with the other arm of said bell-crank lever.

7. In a sewing-machine, a pull-off and thread-measuring mechanism comprising 2 lever pivoted at an intermediate point and 1 extending from front to rear of the machine, a needle-block connected by a link to the front end of said lever, a needle-cam and a cam-stud carried by said lever engaging the same to reciprocate said needle, a thread-engaging fork carried by the rear arm of said lever, a tension device from which the thread passes to said fork, a thread-retaining wheel to Whichthe thread passes from said fork, a ratchet Wheel and pawl carried by said threadretaining wheel and adapted to prevent the backward rotation of the latter, a bell-crank lever mounted coaxially with said thread-retaining wheel and having a rearwardly-extending arm carrying a stud adapted to assume variable positions across the path of the thread between the tension device and said fork, a sliding bar projecting from front to rear of the machine and carrying at its front end a presser-foot, a spring causing said presser-foot and bar to be pressed into a for- Ward position, a link connecting the rear end of said bar with the upright arm of said bellcrank lever, a serrated plate 20 carried by said sliding bar, and a serrated locking-dog 21 adapted to engage with said serrated plate during the formation of a stitch and simultaneous operation of the pull-01f mechanism to retain the measuring device in place, substantially as described.

8. In a sewing-machine, the combination of a two-armed lever extending from front to rear of the machine and pivoted at an intermediate point, a needle-block connected to the front arm of the needle and operated thereby, a pull-off fork carrying a thread-engaging stud or roller through which the thread is looped and carried by the rear arm of said lever, a tension device from which the thread is drawn by said pull-01f device, a measuring device comprising a roller movable to variable positions across the path of the thread between said tension device and pull-ofi fork, said measuring device being connected to a spring presser-t'oot which presses against the work and causes said measuring device to assume a varying position in accordance with the thickness of the stock, and stitch-forming mechanism acting in conjunction with the needle mechanism to form a chain-stitch.

In Witness whereof I have hereunto set my hand in the presence of two Witnesses.

JOSEPH LOUIS KIEFFER.

Witnesses:

J. A. MARION, J. ED. RAZE. 

